Published online by Cambridge University Press: 10 July 2009
The insecticidal activities of 13 triphenyltin compounds having the general formula (C6H5)3Sn X were compared with those of other organotin compounds and DDT by exposing adults of Sitophilus oryzae (L.) for 48 hours on filter paper impregnated with 1 per cent, solutions of the compounds in benzene, and by allowing larvae of Tineola bisselliella (Humm.) to feed for 14 days on pieces of woollen cloth impregnated with 1 per cent, by weight of the compounds. The triphenyltin compounds were ineffective as contact insecticides, virtually all the Sitophilus adults surviving, whereas all were killed by DDT. Their effectiveness as stomach poisons varied with the nature of the Group X, mortality after 14 days amongst the Tineola larvae ranging from 76 per cent., for triphenyltin thiophenoxide, down to zero, for hexaphenylditin. All except the latter and triphenyltin sulphide were highly effective moth-proofing agents, the weight lost by the test pieces being less than 5 per cent, of that lost by the untreated control. Tetraphenyltin afforded no protection against Tineola, but tributyltin oxide caused 100 per cent, mortality, apparently by contact action, since none of the test piece was eaten.